package com.markerhub.shiro;

import cn.hutool.json.JSONUtil;
import com.markerhub.common.Result;
import com.markerhub.util.JwtUtils;
import io.jsonwebtoken.Claims;
import org.apache.shiro.authc.AuthenticationException;
import org.apache.shiro.authc.AuthenticationToken;
import org.apache.shiro.authc.ExpiredCredentialsException;
import org.apache.shiro.web.filter.authc.AuthenticatingFilter;
import org.apache.shiro.web.util.WebUtils;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Component;
import org.springframework.util.StringUtils;
import org.springframework.web.bind.annotation.RequestMethod;

import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;

@Component
public class JwtFilter extends AuthenticatingFilter {

    @Autowired
    JwtUtils jwtUtils;

    //实现登录，我们需要生成我们自定义支持的JwtToken
    @Override
    protected AuthenticationToken createToken(ServletRequest servletRequest, ServletResponse servletResponse) throws Exception {
        System.out.println("实现登录-----");
        HttpServletRequest request = (HttpServletRequest) servletRequest;
        String jwt = request.getHeader("Authorization");
        if(StringUtils.isEmpty(jwt)) {
            return null;
        }
        return new JwtToken(jwt);
    }

    //拦截校验，当头部没有Authorization时候，我们直接通过，让注解去进行拦截
    // 不需要自动登录；当带有的时候，首先我们校验jwt的有效性，
    //  没问题我们就直接执行executeLogin方法实现自动登录
    @Override
    protected boolean onAccessDenied(ServletRequest servletRequest, ServletResponse servletResponse) throws Exception {
        System.out.println("拦截校验-------");
        HttpServletRequest request = (HttpServletRequest) servletRequest;
        String jwt = request.getHeader("Authorization");
        if(StringUtils.isEmpty(jwt)) {
            return true;
        }else {
            //校验jwt
            Claims claim = jwtUtils.getClaimByToken(jwt);
            if(claim == null || jwtUtils.isTokenExpired(claim.getExpiration())) {
                throw new ExpiredCredentialsException("token失效,请重新登陆");
            }
            //执行登陆
            return executeLogin(servletRequest,servletResponse);
         }
    }

    //重写此方法 登陆异常的时候抛出我们自定义的信息
    @Override
    protected boolean onLoginFailure(AuthenticationToken token, AuthenticationException e, ServletRequest request, ServletResponse response) {
        //获得异常信息
        Throwable throwable = e.getCause() == null?e:e.getCause();
        Result result = Result.error(throwable.getMessage());
        //封装起来
        String json = JSONUtil.toJsonStr(result);

        HttpServletResponse httpServletResponse = (HttpServletResponse)response;
        try {
            httpServletResponse.getWriter().print(json);
        } catch (IOException ex) {
            ex.printStackTrace();
        }

        return false;
    }

    /**
     * 对跨域提供支持
     * 拦截器的前置拦截，因为我们是前后端分析项目，项目中除了需要跨域全局配置之外，
     * 我们再拦截器中也需要提供跨域支持。这样，拦截器才不会在进入Controller之前就被限制了。
     */
    @Override
    protected boolean preHandle(ServletRequest request, ServletResponse response) throws Exception {
        System.out.println("跨域------");
        HttpServletRequest httpServletRequest = WebUtils.toHttp(request);
        HttpServletResponse httpServletResponse = WebUtils.toHttp(response);
        httpServletResponse.setHeader("Access-control-Allow-Origin", httpServletRequest.getHeader("Origin"));
        httpServletResponse.setHeader("Access-Control-Allow-Methods", "GET,POST,OPTIONS,PUT,DELETE");
        httpServletResponse.setHeader("Access-Control-Allow-Headers", httpServletRequest.getHeader("Access-Control-Request-Headers"));
        // 跨域时会首先发送一个OPTIONS请求，这里我们给OPTIONS请求直接返回正常状态
        if (httpServletRequest.getMethod().equals(RequestMethod.OPTIONS.name())) {
            httpServletResponse.setStatus(org.springframework.http.HttpStatus.OK.value());
            return false;
        }
        return super.preHandle(request, response);
    }

}
